Don't duplicate OS::ActivationFrameAlignment() for every POSIX platform.

src/platform-openbsd.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 46 matching lines @@
 #include "vm-state-inl.h"
 
 
 namespace v8 {
 namespace internal {
 
 
 static Mutex* limit_mutex = NULL;
 
 
-static void* GetRandomMmapAddr() {
-  Isolate* isolate = Isolate::UncheckedCurrent();
-  // Note that the current isolate isn't set up in a call path via
-  // CpuFeatures::Probe. We don't care about randomization in this case because
-  // the code page is immediately freed.
-  if (isolate != NULL) {
-#if V8_TARGET_ARCH_X64
-    uint64_t rnd1 = V8::RandomPrivate(isolate);
-    uint64_t rnd2 = V8::RandomPrivate(isolate);
-    uint64_t raw_addr = (rnd1 << 32) ^ rnd2;
-    // Currently available CPUs have 48 bits of virtual addressing.  Truncate
-    // the hint address to 46 bits to give the kernel a fighting chance of
-    // fulfilling our placement request.
-    raw_addr &= V8_UINT64_C(0x3ffffffff000);
-#else
-    uint32_t raw_addr = V8::RandomPrivate(isolate);
-    // The range 0x20000000 - 0x60000000 is relatively unpopulated across a
-    // variety of ASLR modes (PAE kernel, NX compat mode, etc).
-    raw_addr &= 0x3ffff000;
-    raw_addr += 0x20000000;
-#endif
-    return reinterpret_cast<void*>(raw_addr);
-  }
-  return NULL;
-}
-
-
-int OS::ActivationFrameAlignment() {
-  // With gcc 4.4 the tree vectorization optimizer can generate code
-  // that requires 16 byte alignment such as movdqa on x86.
-  return 16;
-}
-
-
 const char* OS::LocalTimezone(double time) {
   if (std::isnan(time)) return "";
   time_t tv = static_cast<time_t>(floor(time/msPerSecond));
   struct tm* t = localtime(&tv);
   if (NULL == t) return "";
   return t->tm_zone;
 }
 
 
 double OS::LocalTimeOffset() {
@@ skipping 28 matching lines @@
 bool OS::IsOutsideAllocatedSpace(void* address) {
   return address < lowest_ever_allocated || address >= highest_ever_allocated;
 }
 
 
 void* OS::Allocate(const size_t requested,
                    size_t* allocated,
                    bool is_executable) {
   const size_t msize = RoundUp(requested, AllocateAlignment());
   int prot = PROT_READ | PROT_WRITE | (is_executable ? PROT_EXEC : 0);
-  void* addr = GetRandomMmapAddr();
+  void* addr = OS::GetRandomMmapAddr();
   void* mbase = mmap(addr, msize, prot, MAP_PRIVATE | MAP_ANON, -1, 0);
   if (mbase == MAP_FAILED) {
     LOG(i::Isolate::Current(),
         StringEvent("OS::Allocate", "mmap failed"));
     return NULL;
   }
   *allocated = msize;
   UpdateAllocatedSpaceLimits(mbase, msize);
   return mbase;
 }
@@ skipping 174 matching lines @@
 
 VirtualMemory::VirtualMemory(size_t size)
     : address_(ReserveRegion(size)), size_(size) { }
 
 
 VirtualMemory::VirtualMemory(size_t size, size_t alignment)
     : address_(NULL), size_(0) {
   ASSERT(IsAligned(alignment, static_cast<intptr_t>(OS::AllocateAlignment())));
   size_t request_size = RoundUp(size + alignment,
                                 static_cast<intptr_t>(OS::AllocateAlignment()));
-  void* reservation = mmap(GetRandomMmapAddr(),
+  void* reservation = mmap(OS::GetRandomMmapAddr(),
                            request_size,
                            PROT_NONE,
                            MAP_PRIVATE | MAP_ANON | MAP_NORESERVE,
                            kMmapFd,
                            kMmapFdOffset);
   if (reservation == MAP_FAILED) return;
 
   Address base = static_cast<Address>(reservation);
   Address aligned_base = RoundUp(base, alignment);
   ASSERT_LE(base, aligned_base);
@@ skipping 51 matching lines @@
 }
 
 
 bool VirtualMemory::Guard(void* address) {
   OS::Guard(address, OS::CommitPageSize());
   return true;
 }
 
 
 void* VirtualMemory::ReserveRegion(size_t size) {
-  void* result = mmap(GetRandomMmapAddr(),
+  void* result = mmap(OS::GetRandomMmapAddr(),
                       size,
                       PROT_NONE,
                       MAP_PRIVATE | MAP_ANON | MAP_NORESERVE,
                       kMmapFd,
                       kMmapFdOffset);
 
   if (result == MAP_FAILED) return NULL;
 
   return result;
 }
@@ skipping 112 matching lines @@
   limit_mutex = CreateMutex();
 }
 
 
 void OS::TearDown() {
   delete limit_mutex;
 }
 
 
 } }  // namespace v8::internal